1. Field of the Invention
The present invention generally relates to cooling systems. More specifically, the present invention relates to a system and method for providing cooling systems with heat exchangers, wherein the cooling system is preferably a liquid cooling system that lowers the temperature of an integrated circuit package or surfaces of semiconductor devices.
2. Discussion of the Related Art
In recent years, electronic devices and systems have been made to operate with faster and faster speed. Rapid development in high power integrated circuit (IC) chips, such as high-end processors or processors for high power systems, are made to meet the increasing demands on fast performance and decrease size of electronic systems. The demands have led to a decrease in the size and weight of chips, while at the same time the number of elements on the chips has grown considerably. This leads to increase in heat generation.
Generally, there are two categories of cooling mechanisms for an electronic system: air cooling and liquid cooling. Air cooling has the advantage of being relatively inexpensive and easy to incorporate into most system designs. Air cooling is implemented for most of the low to medium power electronic systems, and it is further divided into natural convection cooling and forced convention cooling. Natural convection cooling is usually implemented for extremely low power systems, where thermal density variations caused by heating of the systems induce air movement sufficient to carry away excess heat. On the other hand, for systems with higher power levels, forced convection cooling is utilized with a fan or blower that creates air flow, which enhances heat transfer coefficients and increases the amount of heat dissipation.
As the performance of the IC chips become faster and the elements on the IC chips become denser, power dissipation and heat generation by the IC chips increases. While air cooling is sufficient for most low to medium power electronic systems, the increase in heat generation in high power electronic systems and high-end processors is driving a requirement for liquid cooling solutions. Two types of liquid cooling are generally implemented: direct liquid cooling and indirect liquid cooling. In direct liquid cooling, the chips come in direct contact with the coolant, whereas in indirect liquid cooling, heat transfer is accomplished via an indirect manner and the chips do not come in contact with the coolant. Instead, a heat exchanger may be implemented to remove heat from the liquid, indirectly removing heat from the chips. Of the two types of liquid cooling mechanisms, direct liquid cooling is by far the most effective, but it runs into the problems of selecting an electrically nonconductive coolant and degradation of coolant because of chemical reactions. On the other hand, the current method of implementing an indirect liquid cooling involves complicated and time-consuming manufacturing processes, making it expensive for mainstream applications to adapt liquid cooling solutions as means of dissipating heat.
One of the complicated and time-consuming manufacturing processes is associated with the making of a heat exchanger that is specifically adapted for a liquid cooling system. A heat exchanger serves to radiate heat from the liquid flowing therethrough. FIG. 1 shows a top view of a prior art design of a heat exchanger 9 in a liquid cooling system. The prior art heat exchanger 9 is made of metal, and it comprises vertical metal fins 5, metal base tubes 3 and tube elbows 7. The prior art heat exchanger 9 is connected to tubing 1, which carries hot liquid generated from one portion of the liquid cooling system into the metal base tubes 3. The tube elbows 7 connect neighboring metal base tubes 3 with one another, allowing hot liquid to flow readily through all the metal base tubes 3 of the prior art heat exchanger 9. The vertical metal fins 5 run through the metal base tubes 3, serving to more efficiently radiate heat from the hot liquid as it flows through the metal base tubes 3. Thus, the metal base tubes 3 conducts hot liquid through an array of the horizontal metal fins 5 through a series of bends 7. A metal frame 8 is also assembled over the metal fins 5 to provide additional strength and mounting features.
FIG. 2 illustrates a perspective view of the prior art heat exchanger 9 with horizontal metal fins 5. To form the prior art heat exchanger 9, the metal fins 5 need to be first formed and then assemble onto the metal base tubes 3. The manufacturing and assembly require a number of steps to be performed. For example, stamping is needed to form thin metal fins. Additionally, holes 4 need to be introduced in the metal fins 5 to allow tube insertion of the metal base tubes 3 through the metal fins 5. To provide proper seal, the metal fins 5 are then either pressed fit or brazed to the metal base tubes 3. Sometimes, the metal base tubes 3 are required to be inserted through the metal fins 5 prior to the tube elbows 7 being soldered into place, which further complicates the assembly process. Furthermore, mounting features, such as brackets and screw holes, need to be assembled onto the subassembly as a final step. These manufacturing and assembly processes are complicated and time-consuming, making the prior art heat exchanger 9 expensive to make and labor intensive and not scalable to high volume manufacturing (HVM).
Therefore, there is a need for a new system and method of providing liquid cooling system that is less complicated to construct, which would be less expensive by being machine intensive instead of labor intensive in high volume manufacturing.